BACKGROUND OF THE INVENTION There is no prior technology for getting air out of intravenous (IV) tubing and preventing the air from intravenous (IV) tubing from entering healthcare patients' veins. Presently, healthcare practitioners tap intravenous (IV) tubing with their fingernails to prime new intravenous (IV) tubing and to push air out of the intravenous (IV) tubing. If healthcare practitioners cannot get the air out of the intravenous (IV) tubing, then they must prime new intravenous (IV) tubing; however, this leads to unnecessary multiple injections to healthcare patients' veins.
According to Dr. John Peter Gruen of the Department of Neurosurgery at the University of Southern California, air embolism is “the entry of air into the blood stream with formation of bubbles that can reach sufficient volume that they interfere with normal pumping of blood by the heart.” Moreover, according to Dr. T. Kapoor and Dr. G. Gutierrez of the Department of Internal Medicine at George Washington University, air embolism is “a cause of the systemic inflammatory response syndrome.” Although many occurrences of air embolism are asymptomatic, entrainment of large quantities of air can lead to cardiovascular collapse, severe neurological injury, and even death. The mechanism of death from massive air embolism is circulatory obstruction and cardiovascular collapse resulting from air trapped in the right ventricular outflow tract.
Venous air embolism that does not cause immediate death can cause paradoxical embolization by acutely increasing right atrial pressure resulting in right to left shunt through a patent foramen ovale. Pulmonary microvascular occlusion can also occur; the air can produce increasing obstruction to blood flow, undergo resorption, or result in increased dead space. Bronchoconstriction may result from release of endothelial mediators, complement production, and cytokine release. Bronchoconstriction results in increased airway pressure and wheezing. During spontaneous respiration, slow entrainment of air that causes obstruction of 10% of the pulmonary circulation causes a “gasp” reflex that results in chest pain and tachypnea. The resulting decrease in intrathoracic pressure and right atrial pressure can increase the rate of air entrainment. Other manifestations of air embolism include hypoxemia, hypercapnia, and decreased ETCO2 (end-tidal carbon dioxide) due to increased functional dead space. Hypotension, cardiac dysrhythmias, and cardiovascular collapse occur as air entrainment continues.
Morbidity and mortality from air embolism are directly related to the size of the embolus and the rate of entry. Doses of air greater than fifty milliliters (50 ml) or one milliliter per kilogram (1 ml/kg) cause hypotension and dysrhythmias. Three hundred milliliters (300 ml) of air entrained rapidly can be lethal.
U.S. Pat. No. 6,261,267 of Chen discloses an IV container spike and drip chamber assembly, which includes an automatic shut off mechanism to allow nurses to change the fluid container without removing the catheter from the patient. The automatic shut off mechanism comprises a floating ball capable of being supported by or floating in the fluid due to the buoyancy of the fluid. The IV container spike also includes an air vent which allows the air in the drip chamber to vent when nurses want to change the container of medical fluid. As the medicinal fluid is gradually reduced in level in the drip chamber, the floating ball is lowered thereby and when the floating ball reaches the bottom of the drip chamber, the floating ball blocks the outlet so as to stop the injection.
OBJECTS OF THE INVENTION It is an object of the invention to provide a mechanism to take air out of intravenous (IV) tubing and keep air out of healthcare patients' veins, i.e., air that has built up either from: 1) the solution or medication running low from the intravenous (IV) bag, or 2) improper priming of the initial intravenous (IV) drip.
It is also an object of this invention to allow healthcare practitioners to change intravenous (IV) bags without removing the needle from the patient's vein in order to prime new intravenous (IV) tubing.
SUMMARY OF THE INVENTION This invention solves a healthcare safety issue, i.e., air embolism is a potentially lethal complication caused by preventable negligence. Air embolism is when air bubbles accumulate in the blood stream and hinder the circulation of blood. This invention prevents any air from entering a healthcare patient's blood stream and causing air embolism, also known as venous air embolism.
Use of this invention will lead to increased productivity of intravenous (IV) drips because the invention allows for a seamless interchange of medications and solutions. Moreover, use of the invention will decrease the unproductive employment of healthcare practitioners' skills and decrease the overburdening of healthcare practitioners' time. Therefore, use of this invention will lead to a more effective use of healthcare practitioners' time and talents and to the effective prevention of air embolism.
In accordance with these and other aspects of the invention, there is disclosed a valve for controlling the flow of fluid into a patient and preventing the introduction of air into the patient. The valve comprises a chamber comprising a bottom and a top base of the chamber. The top base is attached to the top of the chamber, has a top opening there through, and is adapted to facilitate the flow of the fluid through the top opening and the chamber. Further, a bottom base is attached to the bottom of the chamber and has a bottom opening disposed there through. A sphere is disposed within the chamber, whereby the sphere is adapted to float upon the fluid introduced, and is dimensioned and configured with respect to the bottom opening to prevent the discharge of air from the chamber and through the bottom opening when there is no fluid in the chamber and the sphere is disposed in its blocking position with respect to the bottom opening. Further, a stop mechanism is provided for preventing the sphere from blocking the top opening when the chamber is filled with the fluid. A mechanism is disposed adjacent the bottom opening to facilitate the withdrawal of air flowing through the chamber to enhance the amount of air that may be withdrawn from the chamber.
In a further aspect of this invention, a fluid valve is disclosed for preventing the flow of air into a patient. The valve comprises a chamber, which includes a top and a bottom. The top has a top opening introducing the fluid into the chamber and the bottom has a bottom opening for discharging the fluid from the chamber and into the patient. Further, a sphere is disposed in the chamber and adapted to rise and fall therein as the fluid is respectively introduced into or discharged from chamber, whereby the bottom opening is locked to prevent the discharge of air from the chamber and into the patient. A mechanism is provided to prevent the sphere from blocking the top opening and capturing air in the chamber when the chamber is filled with the fluid. The mechanism is disposed in a relatively close position to the upper door to enhance the free flow of fluid through the chamber.
In a still further aspect of this invention, the valve includes the bottom base, which is adapted to be directly connected to a catheter.
BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention and further features thereof, reference is made to the following detailed description of the invention to be read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a detailed view of an illustrative embodiment of the invention;
FIG. 2 is a cross-sectional view of an illustrative embodiment of the invention; and
FIG. 3 is an assembly view of an illustrative embodiment of the invention, wherein the connection of this invention to its related apparatus is illustrated.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THIS INVENTION Referring now to the drawings and in particular toFIG. 1, there is shown an illustrative embodiment of anair valve10, which may be used to extract air from intravenous (IV) tubing and prevent any air from being introduced into a patient's veins.Air valve10 comprises a universalcylindrical drip chamber12 with a free-floating sphere14 inside, a horizontalcircular ring16 attached to fourposts18 that extend from the top of the inside of the drip chamber, and anexternal port20 with a removable cap-cover22 at the base ofvalve10. As will be explained, thering16 andposts18 form a stop mechanism to prevent thesphere14 from blocking. Theair valve10 also comprises aspike24 at the top of thecylindrical drip chamber12, having atop base28, and abottom base26 at the bottom of thecylindrical drip chamber12.
In an illustrative embodiment, all parts of the valve may be made by any of the following plastic polymers: polyethylene; (non-DEHP) PVC; or (non-Di-2-Ethylhexl Phthalate) Polyvinyl Chloride.
Referring now toFIG. 2, there is shown a cross-sectioned view of the illustrative embodiment with illustrative dimensions of theair valve10 as shown inFIG. 1. Even though illustrative dimensions are set out inFIG. 2, these dimensions are not shown to scale. Thecylindrical drip chamber12 measures one-half (½″) inch in internal diameter D1 and two (2″) inches in length L1. The hollowedspike24 at the top of thecylindrical drip chamber12 measures one-eighth (⅛″) inch in external diameter D2 and one-half (½″) inch in length L2 and has an internal diameter of one-ninth ( 1/9″) inch D3. Thespike24 has abase28 measuring three-fifth (⅗″) inch in diameter D4 and one-eighth (⅛″) inch in height L3 at the top of thecylindrical drip chamber12. Thesphere14, measuring two-fifth (⅖″) inch in diameter (D5), is free-floating inside thecylindrical drip chamber12 and is hollow in order to ensure a net upward buoyant force regardless of the type of liquid that may be in the drip chamber. The horizontalcircular ring16 measures one-fourth (¼″) inch in diameter D6 and one-sixteenth ( 1/16″) inch in thickness L4. It is suspended one-half (½″) inch L5 down from thespike base28. The fourposts18, which measure one-sixteenth ( 1/16″) inch in width W1 and one-half (½″) inch in length L5, are connected to the inside of thespike base28 at their top ends and attached to the horizontalcircular ring16 at their bottom ends. Theexternal port20, measuring one-half (½″) inch in width W2 and having an internal diameter equal to an 15 gauge regular wall needle D7 and an external diameter of one-sixteenth ( 1/16″) inch D8, is located on the side of thecylindrical drip chamber12, one-eighth (⅛″) inch L6 from the bottom of thecylindrical drip chamber12. Theexternal port20 comprises a removable cap-cover22 having an internal diameter of one-sixteenth ( 1/16″) inch D8. Therear port26 on the underside-bottom of thecylindrical drip chamber12 measures one-half (½″) inch in length L7 and one-eighth (⅛″) inch in external diameter D9, and has an internal diameter equal to an 15 gauge regular wall needle D10.
Referring now toFIG. 3, there is shown an illustrative embodiment of a connection of theair valve10 to an intravenous (IV)bag36. Theair valve10 is attached at one end to the intravenous (IV)tubing32 so that theair valve10 is directly above theinjection site38, where a needle is inserted into a patient's vein, or above the cannula that is attached to a needle that is inserted into a patient's vein. Thespike24 of theair valve10 is inserted directly into the lowest end of the intravenous (IV)tubing32 that hangs from the intravenous (IV)bag36. Therear port26 ofair valve10 is inserted directly into theinjection site38 or into a Male Luer Lock Adapter attached to a Lever Lock Cannula that is connected to theinjection site38. The cap-cover22 for theexternal port20 is removed when theexternal port20 is being accessed and replaced over theexternal port20 when theexternal port20 is not being accessed. The Wen U.S. Pat. No. 6,261,267 of Wen discloses in contrast the direct connection of the needle to the bottom base orcannula26, that his needle interconnected by tubing, a roller clamp and a luer connection to the Wen's needle or catheter. The advantage of direct connection of the needle to the bottom baser of this invention, as compared to Wen's device, is that more air can be trapped in the extended fluid conduit as constructed by Wen.
Thesphere14 inside theair valve10 floats when there is sufficient liquid inside thedrip chamber12 to lift the sphere from its seat. Since thesphere14 is hollow, a net upward buoyant force is formed when thedrip chamber12 is filled with liquid, making thesphere14 float and thereby allowing solution or medication to pass through an opening in thebottom base26 to the patient. Thesphere14 seals off thedrip chamber12 from thebottom base26 when there is no liquid inside thedrip chamber12. Since thesphere14 is denser than air but less dense than the solution or medication, the weight of thesphere14 makes it fall when there is no liquid inside thedrip chamber12. And since thesphere14 is greater in diameter than therear port26 that leads to theinjection site38, thesphere14, when it falls, prevents any air from passing through thebottom base26 to the patient. The horizontalcircular ring16, which is attached to the fourposts18, acts as a float stop for thesphere14. When thesphere14 is floating, the horizontalcircular ring16 stops thesphere14 from floating all the way to the top of thedrip chamber12 and thereby does not allow thesphere14 to seal off the solution or medication flowing through thespike24 at the top of thedrip chamber12. Since the “float-stop” is composed of posts instead of a cylinder or casing, liquid can flow from thespike24 pass around the fourposts18 and continue around the sides of thering16 into thedrip chamber12, regardless of the position of thesphere14.
The U.S. Pat. No. 6,261,267 of Wen discloses, as noted above, an automatic shut off valve, and comprises a ball and a flange which keeps the ball from floating to the top when the fluid is introduced into the drip chamber. In the Wen patent, the flange in disposed adjacent the lower opening through which the fluid is discharged from the drip chamber. On the other hand, there is shown inFIGS. 2 and 3 of this document the stop mechanism comprising theposts18 and thering16 which is disposed at least closer to the top opening of thetop base28, than to the bottom based26. The flange of the Wen patent may, if the valve is disposed in another than vertical position, may lodged to block or to interrupt the fluid flow. In contrast, the stop mechanism of this invention is disposed more remotely from thebottom base26 than thetop base28 and will not interrupt the fluid through the chamber and the opening in thebottom base26.
Theexternal port20 extracts air from the intravenous (IV)tubing32 with the use of asyringe30. When solution or medication begins to enter the intravenous (IV)tubing32 from the intravenous (IV)bag36, a healthcare practitioner will insert asyringe30 with a regular wall needle (illustratively 15 gauge) into theexternal port20 and extract the air from theair valve10 until there is only solution or medication remaining in the intravenous (IV)tubing32 and theair valve10. The cap-cover22 for theexternal port20 will be removed when theexternal port20 is being accessed in order to insert a syringe with a regular wall needle to extract the air from theair valve10. Thecap cover22 is then replaced over theexternal port20 when theexternal port20 is not being accessed, thereby preventing any air from entering theair valve10 through theexternal port20. Thespike24 makes a seamless interchange between theair valve10 and the intravenous (IV)tubing32 attached to the hanging intravenous (IV)bag36; it acts as a conduit for the solution or medication flowing from the hanging intravenous (IV)bag36 and attached intravenous (IV)tubing32 into theair valve10. Thedrip chamber12 contains thesphere14 that prevents any air from passing into the patient and the horizontalcircular ring16 attached to the fourposts18 that prevents thesphere14 from floating to the top and sealing off the solution or medication flowing from the hanging intravenous (IV)bag36 and attached intravenous (IV)tubing32. Thedrip chamber12 also collects the solution or medication which flows through thespike24 from the hanging intravenous (IV)bag36 and attached intravenous (IV)tubing32 and allows thesphere14 to float. Therear port26 makes a seamless interchange between theair valve10 and theinjection site38; it acts as a conduit for the solution or medication flowing from theair valve10 into theinjection site38 and then into the patient's vein.
The U.S. Pat. No. 3,261,267 of Wen also discloses a vent that permits the release of air. This vent is disposed on the top of Wen's value and remotely from its automatic shut off mechanism. In contrast, the invention disclosed by this document positions its air release mechanism in the form of theexternal port20 as shown inFIGS. 2 and 3 as being disposed adjacent the bottom base23. The advantage of this placement is that the medical personnel operating the syringe can extract air more efficiently as the fluid is being introduced into itsdrip chamber12. As the fluid is being pored into the chamber, it initially traps the air at the bottom of thechamber12, whereby it is relatively available to be with drawn by a syringe that is inserted into theport20, i.e., at the bottom of thechamber12. Only after the fluid displaces the air from the bottom of thechamber12 and rises to the top of the chamber, can the vent of the Wen device begin to withdraw the air from its chamber thereby slowing its process for air removal.
Although the present invention has been described in terms of various embodiments, it is not intended that the invention be limited to these embodiments. Modification within the spirit of the inventions will be apparent to those skilled in the art. The scope of the present invention is defined by the claims that follow.